1. Field of the Invention
The present invention generally relates to the field of semiconductor integrated circuit (IC) packaging. In particular, the present invention relates to an integrated circuit package with a leadframe enhancement and a method of assembling the same in order to provide high package stability.
2. Discussion of Related Art
Semiconductors are materials that have characteristics of both insulators and conductors. In today's technology, semiconductor materials have become extremely important as the basis for transistors, diodes, and other solid-state devices. Semiconductors are usually made from germanium or silicon, but selenium and copper oxide, as well as other materials, are also used. When properly made, semiconductors will conduct electricity in one direction better than they will in the other direction.
Semiconductor devices and ICs are made up of components, such as transistors and diodes, and elements such as resistors and capacitors, linked together by conductive connections to form one or more functional circuits. Interconnects on an IC chip serve the same function as the wiring in a conventional circuit.
Once the components of an IC package have been assembled, the package is typically sealed by plastic encapsulant in order to improve the strength of the package and to provide necessary protection to components within.
U.S. Pat. No. 5,894,108 to Mostafazadeh discloses a typical encapsulated IC package. IC package 100, illustrated in FIGS. 1A and 1B, is one example of a typical IC package. The package 100 comprises a die pad 103, a plurality of leads 101, and an IC chip 102 mounted to the die pad through an adhesive layer 107. The IC chip 102 is electrically joined to the plurality of leads 101 through a plurality of wires 110. The entire package is protected by an encapsulant 105, which hardens to protect the elements within and to add support to the package as a whole.
A problem associated with IC packages encapsulated in the conventional way, such as IC package 100 of FIGS. 1A and 1B, is the separation of the hardened encapsulant 105 from the leads 101 at regions of high stress. As shown in FIG. 1B, when the components of the package 100 are subjected to the mechanical and thermal stresses of normal use, the hardened encapsulant 105 may separate from the leads 101 at points of high stress, such as point 106. These separations increase over time and can effect the functioning and quality of the package as a whole.